This project is a investigation of virulence in Vibrio cholerae. Mutants deficient in virulence are being isolated and studied in several animal and in vitro systems. Since V. cholerae does not penetrate gut tissue, we can study survival, multiplication and nutrition of Vibrios in the gut. We also are studying the attachment of vibrios to gut tissue. One of our goals is to derive vibrio strains useful for improved cholera vaccines. BIBLIOGRAPHIC REFERENCES: Baselski, V., R. Briggs, and C. Parker. 1977. Intestinal fluid accumulation in infant mice induced by oral challenge with Vibrio cholerae or cholera toxin. Infection and Immunity: in press. Guentzel, M., L. Field, G. Cole and L. Berry. 1977. The localization of Vibrio cholerae in the ileum of infant mice. Scanning Electron Microscopy 1977. Vol.2: 275-282.